cluster name generated by cilium cli can be problematic in eks and gke

[littlejo]

Bug report

with cilium-cli, cluster.name helm values is generated using context kubeconfig.

Example of default context in eks:

arn:aws:eks:us-east-1:123456789:cluster/cluster-name

i'm not sure ":" or "/" is allowed in cluster name but it didn't work.

The context for gke can be more than 64 characters (i suppose it's the limit i tested with 69), so it also failed.